class_docstr: This `Field` represents a list of string tokens.  Before constructing this object, you need
  to tokenize raw strings using a :class:`~allennlp.data.tokenizers.tokenizer.Tokenizer`.
  
  Because string tokens can be represented as indexed arrays in a number of ways, we also take a
  dictionary of :class:`~allennlp.data.token_indexers.token_indexer.TokenIndexer`
  objects that will be used to convert the tokens into indices.
  Each `TokenIndexer` could represent each token as a single ID, or a list of character IDs, or
  something else.
  
  This field will get converted into a dictionary of arrays, one for each `TokenIndexer`.  A
  `SingleIdTokenIndexer` produces an array of shape (num_tokens,), while a
  `TokenCharactersIndexer` produces an array of shape (num_tokens, num_characters).
docstr: Overrides the behavior of `duplicate` so that `self._token_indexers` won't
  actually be deep-copied.
  
  Not only would it be extremely inefficient to deep-copy the token indexers,
  but it also fails in many cases since some tokenizers (like those used in
  the 'transformers' lib) cannot actually be deep-copied.
docstr_tok: ["Overrides","the","behavior","of","`","duplicate","`","so","that","`","self._token_indexers","`","won't","actually","be","deep-copied",".","Not","only","would","it","be","extremely","inefficient","to","deep-copy","the","token","indexers",",","but","it","also","fails","in","many","cases","since","some","tokenizers","(","like","those","used","in","the","'transformers","'","lib",")","can","not","actually","be","deep-copied","."]
code: def duplicate(self):
      """
      Overrides the behavior of `duplicate` so that `self._token_indexers` won't
      actually be deep-copied.
  
      Not only would it be extremely inefficient to deep-copy the token indexers,
      but it also fails in many cases since some tokenizers (like those used in
      the 'transformers' lib) cannot actually be deep-copied.
      """
      if self._token_indexers is not None:
          new = TextField(
              deepcopy(self.tokens),
              {k: v for k, v in self._token_indexers.items()},
          )
      else:
          new = TextField(deepcopy(self.tokens))
      new._indexed_tokens = deepcopy(self._indexed_tokens)
      return new
  
imports: from collections import defaultdict
  from copy import deepcopy
  from typing import Dict, List, Optional, Iterator
  import textwrap
  from spacy.tokens import Token
  import torch
  from allennlp.common.checks import ConfigurationError
  from allennlp.data.fields.sequence_field import SequenceField
  from allennlp.data.tokenizers import Token
  from allennlp.data.token_indexers.token_indexer import TokenIndexer, IndexedTokenList
  from allennlp.data.vocabulary import Vocabulary
  from allennlp.nn import util
label_desc: Use image node_id 15 for calling the TextField obj's underlying member method code with example usage: obj.duplicate() and returns: new